Heel raise exercises are typically performed standing and going up on your toes. There are multiple ways to vary this exercise. Using approximately 400-500 words, describe the difference between performing heel raises with your knees straight versus you

Heel raise exercises are typically performed standing and going up on your toes. There are multiple ways to vary this exercise. 

Using approximately 400-500 words, describe the difference between performing heel raises with your knees straight versus your knees bent. What muscles are being activated with each activity? With this knowledge, how would it change the way these muscles get stretched? Include at least two scholarly references (using APA formatting and style) to guide your answers.
Cite all sources used in APA format. Sources should be evidence-based research from medical journals. WebMD, Wikipedia, etc. ARE NOT VALID SOURCES. Paper must be typed,

Times New Roman, 

12pt font, 

doubled spaced, 

1 inch margins.